(a) Field of the Invention
The present invention relates generally to an image scanner, more particularly, to a scanner generating both a primary image and an auxiliary image to correct the damaged image generated from a scratched document.
(b) Description of the Prior Art
At the present time, the scanning device is quite advanced. It can not only convert the original images into digital data but also correct damaged images scanned from scratched documents to produce high quality image data. For example, Applied Science Fiction Co. proposed a technology called Digital Image Correction Enhancement (ICE). The ICE technology can receive the primary image and damaged image from an image scanner and correct the primary image according the damaged image. The primary image and damaged image are generated by scanning typical film with visible light and Infrared (850 nm), respectively.
Because the damaged spots, for example scratched on film, will appear within the damaged image when scanned from the film, the ICE technology can correct the primary image according the damaged image to generate the corrected image without scratches. FIGS. 7 and 8, show the optical path for both a transparent scanner and a reflective scanner. As shown in the figures, both the transparent and reflective scanners need a light source to provide the light beams for scanning and an image sensor module to catch the image.
The ICE technology mentioned above makes use of the different optical characteristics between infrared ray (850 nm wave length) and visible light for typical film and focuses on the different penetrating character from both infrared rays and visible light. Hence, the primary image is generated at illumination of visible light and the damaged image is generated at illumination of infrared ray, respectively. However, it may lose this optical feature while working with a non-transparent document. Therefore, it is only good for typical films but not for typical reflective documents or special films like photos or film for infrared ray. Additionally, the scanning device with ICE technology should carry both visible light and infrared ray sources to generate the primary image and damaged image.